Human Brain Dynamics Dissociate Early Perceptual and Late Motor-Related Stages of Affordance Processing

Abstract

Affordances, the opportunity for action offered by the environment to an agent, are vital for meaningful behavior and exist in every interaction with the environment. There is an ongoing debate in the field about whether the perception of affordances is an automated process. Some studies suggest that affordance perception is an automated process that is independent from the visual context and bodily interaction with the environment, while others argue that it is modulated by the visual and motor context in which affordances are perceived. The present paper aims to resolve this debate by examining affordance automaticity from the perspective of sensorimotor time windows. We replicated a previous study on affordance perception in which participants actively moved through doors of different width in immersive 3D virtual environments. To investigate the impact of different forms of bodily interactions with an environment, i.e., the movement context (physical vs. joystick movement), we used the identical virtual environment from Djebbara and colleagues (2019) but displayed it on a 2D screen with participants moving through different wide doors using the keys on a standard keyboard. We compared components of the event-related potential (ERP) from the continuously recorded electroencephalogram (EEG) that were previously reported to be related to affordance perception of architectural transitions (passable and impassable doors). Comparing early sensory and later motor-related ERPs, our study replicated ERPs reflecting early affordance perception but found differences in later motor-related components. These results indicate a shift from automated perception of affordances during early sensorimotor time windows to movement context dependence of affordance perception at later stages suggesting that affordance perception is a dynamic and flexible process that changes over sensorimotor stages.